Hello,
Pulling KOEO codes 41, 42, 65 and 86, lean condition, no EGO switching, etc. all likely related to the same problem, unmetered air.
I think I have covered most of the bases here... with the engine base timing at 10d bdc and the throttle set up to ~1000 rpm with IAC unplugged, when I plug the IAC back in the car idles at ~2000 rpm (the spout connector is also back in). Because I find 2000 rpms annoying at a stop, I have been setting the throttle plate adjustment out of spec to keep the idle down to 1500 rpms, which I find at least bearable.
The only next step I can think of is pulling the fuel rail out and installing new O-Rings, rubber fittings, etc. on the original injectors. Replacing them is too expensive ($200+), and from what I read in this ng, highly likely a waste of money.
I have been stumped for a while on this, but here is a summary of my findings, looking for input on where to go next.
- Temporarily plugged up the accessory manifold vacuum line on the intake manifold (cuts off the cruise control, brake power assist), no change in idle. The fuel regulator and line holds vacuum, no air leaking.
- Temporarily plugged up the PCV intake on the throttle body, no change in idle. Picked up a working canp solenoid from the junkyard and installed (numbers matched, original was bad), holds vacuum. New PCV valve and grommet (tight fit).
- Just to be sure, temporarily disabled the EGR system by unplugging the EGR valve and EGR solenoid, no change in idle. I wanted to do this because the backpressure line from the vacuum regulator to the exhaust manifold is broken, but I am pretty sure that just means that that the vacuum regulator is not varying the vacuum signal to the EGR valve, but the effect to the EGR system is unknown to me (no vacuum, full vacuum?, passed NJ state emissions regardless).
- Inspected the vane meter to intake tube for pinholes and cracks, etc., none found.
Unless I missed another vacuum subsystem (A/C?), it seems like I eliminated all of the vacuum lines as a possible source of unmetered air.
- Installed a remanufactured vane meter I found in the junkyard, picked up real cheap. No change in idle.
- Installed a new coolant temp sensor, no change in idle.
- Replaced IAC solenoid and TP sensor last year, no change in idle.
- I sprayed some carb gumout on the injectors while the engine was running, no increase in idle, but IMO not really convinced if this would prove anything (i.e., whether or not the injector O-rings are bad).
- Fuel pressure checks out OK with the engine running and key off at
- Checked the upper manifold to lower manifold bolts, throttle body bolts, all tight.
Any ideas?
Thanks in advance, Matt